The invention relates to the field of mobile communications terminals. The invention relates in particular to controlling access to applications and to data in a portable computer terminal, e.g. a mobile telephone.
Mobile terminals, such as multifunction telephones or digital tablets, have various communications resources available that make it possible, for example, to access a telephone network, an Internet network, a GPS network, a near field communication (NFC) interface, a Wi-Fi or Bluetooth network, etc.
Those communications resources are associated with software applications for making use of those services. Some of those applications store the user's personal data, such as photographs, messages, connection identification data, banking data, etc. Such data is critical and needs to be made secure.
For this purpose, mobile telephones are protected by a personal code also known as a PIN code. The PIN code serves to verify the identity of the user and also to block certain functions, such as authentication with the telephone network. It is not possible to use the telephone without the PIN code.
In contrast, once the PIN code has been input, the telephone gives access to all of the personal information. However, it can happen that a relative asks the user to lend the telephone in order to make use of a particular resource, for example access to the Internet when the relative's own telephone does not have such Internet access, or when the relative does not have a telephone. Under certain circumstances, a user may lend a telephone to a person outside the family, or may merely desire to hide certain information that is strictly personal (e.g. messages).
With present-day terminals, this is difficult, since by lending a telephone, a user gives access to all of the user's own personal data. Furthermore, if the person borrowing the telephone desires to use an application that requires an identifier or a password, the user must erase his or her own identification data from the input fields in order to allow that person to make a connection. Once the telephone has been returned, the user must once again input his or her own identifiers into the telephone.
In the field of personal computers, it is known to make use of a multi-session operating system, where each session is associated with a user having predefined access rights and personal data. Nevertheless, using a multi-session mechanism increases the size of the operating system and requires access rights to be defined beforehand. Furthermore, changing from one session to another generally involves several complex manipulations. Thus, such a multi-session mechanism is not appropriate for a situation that is of short duration and exceptional, such as lending a telephone.
Document US 2007/0204224 describes a wireless telephone having a memory that is subdivided between a private portion and a public portion. A password must be input in order to gain access to data in the private portion. In that situation, likewise, it is necessary to define beforehand which data is private and which data is public. That solution is therefore relatively inflexible in configuring access rights. Furthermore, the same data can be both private and public, depending on circumstances. The solution proposed by that document is thus likewise not appropriate for a situation that is of short duration and exceptional, such as lending a telephone.